Bell Helmets Sport intercom amplifier. A super choice for the clubman rally team, as the amplifier combines a mix of simplicity, performance and reliability. The amplifiers noise filters have been extensively tested in a range of rally car cockpits and conditions. The resultant amplifier provides excellent sound quality, for good reliable in-car communications. The amplifier features Individual volume controls for both the driver and co-driver and the unit can be run off a 9v battery or the cars 12v system, via the noise filtered cable supplied. The Bell Sport amplifier is compatible with Bell's range of intercom helmets and any Peltor compatible helmet, headset or practive headset with the relevant Nexus plug. These amplifiers can easily be attached to your rollbar above/behind the crew.